Andradite and Common Opal Physical Properties
Tenacity
Brittle
  
Not Available
  
Solubility
Not Available
  
Not Available
  
Durability
Not Available
  
Not Available
  
Specific Gravity
3.70-4.10
  
1.98-2.50
  
Fracture
Conchoidal, Uneven, Conchoidal, Brittle, ConchoidalArthur Thomas, Gemstones (2009)
  
Conchoidal, Conchoidal, Gemstones of the world (2001)
  
Cleavage
none
  
Not Available
  
Mohs Hardness
6.5-7
  
5.5-6.5
  
Chemical Composition
Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
  
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
  
Andradite and Common Opal Chemical Formula
While comparing Andradite and Common Opal physical properties, the important data you should know is its chemical composition. Since chemical formula defines the molecular structure of the crystal, most of the physical properties like color, tenacity, solubility are governed by Andradite and Common Opal chemical formula.
- Chemical formula of Andradite- Ca 3Fe 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
- Chemical formula of Common Opal- SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Andradite and Common Opal Specific Gravity
Another important criteria for qualitative analysis of gemstones is Andradite and Common Opal Specific gravity. Specific gravity is the relative density of a gemstone compared with respect to density of water. Gemologists use Andradite and Common Opal Optical Properties during the identification of gemstone. Specific gravity of Andradite is 1.98-2.50 whereas that of Common Opal is 1.98-2.50.